This invention relates generally to rotary valves and air locks, and more particularly to such valves as are used in feeding or controlling the flow of powdered or granular material in material handling systems or equipment.
In many industries wherein powdered or granular material is conveyed in a conduit system, such as in some food processing plants, it is necessary that a high degree of sanitation and cleanliness be maintained. For this reason, where moving mechanical parts are used, it is important that these be sealed to protect material in the system from any exterior source of contamination.
Rotary valves of the type including veined rotors for use as air locks and feeding or flow control valves are well known, and have housings which include main housing sections and opposite end sections each of which are bolted to the main housing sections. Many of these require gaskets for sealing and difficulty has been experienced in economically producing such valves wherein the rotary valving element is maintained in concentric relation to the cylindrical chamber wall of the housing, during use. Other problems include leakage of bearing lubricant for the rotary valve shafts to the interior of the valves.
An important object of this invention is the provision of a rotary valve having a housing which can be economically produced with a minimum of machining of the parts.
Another object of this invention is the provision of a valve in which the axis of the valving rotor will not shift out of alignment with the axis of the valve chamber during use.
Still another object of this invention is the provision of a rotary valve the parts of the housing of which can be secured together in sealing engagement with the use of a minimum number of fasteners.